The invention relates to a bore-hole pump with a head part and a foot part.
Bore-hole pumps of this type are provided for delivering water out of earth bore-holes, typically wells. All water-leading components thereby consist of stainless steel, thus of a corrosion-resistant material, and the other components are at least hermetically encapsulated, e.g. by way of a stainless steel jacket. The construction of the pumps is such that in the working position, thus typically on lowering into an essentially vertically running bore-hole, the lowermost part of the assembly is an electrical drive motor, to which the actual pump connects to the top. The pump comprises a foot part, which on the one hand serves for connection of the pump to the motor, and which on the other hand forms the inlet for the water to be delivered, and which finally, together with the head part arranged at the upper end, serves for clamping in the pump stages located between the head part and foot part.
Such pumps are counted as belonging to the state of the art, and in this context, the pumps of the SP construction series manufactured by the company Grundfos are referred to.
The pump stages of these known pumps are manufactured of stainless steel sheet metal. The motor is likewise encapsulated in stainless steel sheet metal. The foot part which was previously manufactured likewise in laborious manner as a steel sheet metal design of stainless steel, with the current pumps of the SP construction series, are manufactured by stainless steel precision casting. The casting components are quite complicated due to the undercuts, since they need to be manufactured with lost wax.